Recording tape cartridge and drive device

ABSTRACT

In the cartridge, the opening is formed diagonally to an arrow A direction by cutting away a corner portion at a drive device loading side of a case, and the opening faces both the arrow A direction and an arrow B direction. A leader pin and a magnetic tape are drawn out along the minimal length path from the opening. An operation projection of a door of the opening is pushed to move rearward by an operation of loading the case into the drive. The door, which is curvedly formed in a circular arc shape, rotates to turn at an outer side of a pin stand and the reel without deviating from a movement path along the curved form, and opens/closes the opening aperture.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording tape cartridge whichrotatably accommodates a single reel onto which a recording tape such asa magnetic tape or the like is wound.

Further, the present invention relates to a drive device at which theabove-described recording tape cartridge is loaded.

2. Description of the Related Art

Recording tapes such as magnetic tapes and the like are used as externalrecording media for computers and the like. Recording tape cartridgesthat accommodate a single reel on which a recording tape is wound takeup little space when stored and can record large amounts of information,and are employed as such recording tapes.

An opening aperture is formed in a case of such a recording tapecartridge. The recording tape is drawn out through this opening, andwound around a drive device side winding reel. Accordingly, there havebeen various schemes in the prior art for preventing dust and the likefrom ingressing through the opening aperture and adhering to therecording tape.

In a recording tape cartridge 100 shown in FIG. 13, an opening 104 isformed in a side wall 102A of a case 102 (a side wall along a caseloading direction A). This opening 104 is structured to be openable andcloseable by a door 106 which slides along the loading direction (forexamples, refer to Japanese Patent Application Laid-Open (JP-A) Nos.11-297032, 11-213615, 11-242871 and 2000-331403).

However, with this position of the opening aperture 104, it is necessarythat a drive device side operation member turns a leader pin 108 aroundfrom a direction sideward of the case 102 when drawing out the leaderpin 108. The leader pin 108 is a leader member attached at an endportion of a magnetic tape T, which is the recording tape. Therefore, aspace for this turning around by the operation member must be conservedat the drive device. Moreover, a structure for the turning around by theoperation member is complicated, and inevitably leads to an increase insize of the drive device. In addition, another aspect to be consideredis that a drawing-out path of the magnetic tape T to a winding reel 110becomes long.

Alternatively, in a recording tape cartridge 112 shown in FIG. 14, anopening 116 is formed in a front face wall 114A of a case 114 (a forwardwall which faces in case loading direction A). This opening 116 isstructured to be openable and closeable by a swivel-type door 118, whichopens and closes by rotation about a shaft (for examples, refer to JP-A9-039832 and the specification of U.S. Pat. No. 5,332,173).

In this recording tape cartridge 112, because the opening 116 is formedin the front face wall 114A, there is no requirement for a drive deviceside operation member to turn the leader member around from a sidewarddirection when drawing out a magnetic tape T. However, the door 118opens outward by a large amount. Therefore, it is necessary to conservespace at the drive device side such that opening and closing operationsof the door 118 are not impeded. As a result, the drive device becomeslarger.

Further, in a recording tape cartridge 120 shown in FIG. 15, an opening124 is formed by cutting away a corner portion of a case 122. Theopening 124 is structured to be opened and closed directly by a leaderblock 126, which is a leader member connected to an end portion of amagnetic tape T (for examples, refer to Japanese Patent ApplicationPublication (JPB) Nos. 61-61470 and 63-53633).

If the leader block 126 functioned only as a door for closing theopening 124, then the occurrence of damage, soiling or the like at theleader block 126 would not be a problem. However, the leader block 126is a structure which is drawn out as is by an operation member andfitted into a hub 130 of a drive device side winding reel 128.Therefore, when damage or soiling occurs at the leader block 126, theleader block 126 may not fit well with the hub 130, and this may have adeleterious effect on running of the magnetic tape T. Moreover, theleader block 126 structures a portion of a winding surface onto whichthe magnetic tape T is wound. Therefore, there is a risk that, as aresult of the aforementioned damage or soiling, data recorded on themagnetic tape T may be damaged or an unrecordable region may be causedat the magnetic tape T.

In addition, the leader block 126 is anchored only at peripheralportions of the opening 124. Therefore, there is a risk that the leaderblock 126 may fall out if the case 122 is dropped. Moreover, because theleader block 126 is larger in size than a leader pin, there are manymore constraints on the form of the case 122.

SUMMARY OF THE INVENTION

In consideration of the circumstances described above, a primary objectof the present invention is to provide a recording tape cartridge inwhich a covering member, which is capable of reducing size of a spacefor accommodation thereof at a drive device, can open and close anopening aperture of a structure, which is capable of minimizing lengthof a drawing-out path of a recording tape, without interfering with areel and a leader member, and with which drive device side openingmeans, which operates the covering member to open and close the openingaperture, can be provided with a simple construction.

Furthermore, another object of the present invention is to provide adrive device with a simple structure which is capable of reliablyopening and closing the opening aperture, which is for drawing out arecording tape of the recording tape cartridge.

In order to achieve the objects described above, according to a firstaspect of the present invention, a tape cartridge which is insertable ata tape drive, the tape drive being provided with an opening member whichis operably engageable with the tape cartridge at a time of insertion ofthe tape cartridge and carrying out at least one of reading and writingof data, includes: a case which includes a front wall portion facing ina direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion, and angled relative to the cartridge insertion direction;a tape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; and anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the opening member of the tape drive by anoperation of insertion of the tape cartridge.

According to another aspect of the present invention, in a tape drivefor carrying out at least one of reading and writing of data at a tapecartridge that includes: a case which includes a front wall portionfacing in a direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion and angled relative to the cartridge insertion direction; atape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; and anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the tape drive by an operation of insertionof the tape cartridge, the tape drive includes an opening member whichis capable of engaging with the operating portion of the covering memberand moving the covering member in the open position direction at a timeof insertion of the tape cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing overall structure of a recordingtape cartridge relating to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the recording tape cartridgerelating to the embodiment of the present invention.

FIG. 3 is a plan view of a lower case which structures the recordingtape cartridge relating to the embodiment of the present invention.

FIG. 4A is a perspective view, from which a door and the like isremoved, showing a slit of a case which structures the recording tapecartridge relating to the embodiment of the present invention.

FIG. 4B is a perspective view showing a variant example of the slit.

FIG. 4C is a perspective view showing another variant example of theslit.

FIG. 5 is a perspective view, viewed with an upper case removed, showinga state in which an opening, which structures the recording tapecartridge relating to the embodiment of the present invention, is closedby a door.

FIG. 6 is a perspective view, viewed with the upper case removed,showing an open state of the door of the opening which structures therecording tape cartridge relating to the embodiment of the presentinvention.

FIG. 7A is a plan view showing an opening process of the opening of therecording tape cartridge relating to the embodiment of the presentinvention, viewed with the upper case removed, which shows an initialstate of engagement of an engaging protrusion of a drive device with anoperation projection of the door.

FIG. 7B is a plan view showing the same opening process, which shows astate during opening of the opening.

FIG. 7C is a plan view showing the same opening process, which shows astate of complete opening of the opening.

FIG. 8 is a perspective view of a bucket which structures a drive devicerelating to the embodiment of the present invention.

FIG. 9 is a plan view showing a lower case which structures a recordingtape cartridge relating to a variant example of the embodiment of thepresent invention.

FIG. 10A is a plan view showing an opening process of an opening of therecording tape cartridge relating to the variant example of theembodiment of the present invention, viewed with the upper case removed,which shows an initial state of engagement of an engaging protrusion ofa drive device with an operation projection of a door.

FIG. 10B is a plan view showing the same opening process, which shows astate during opening of the opening.

FIG. 10C is a plan view showing the same opening process, which shows astate of complete opening of the opening.

FIG. 11 is a perspective view showing a yet another variant example ofthe slit which structures the recording tape cartridge relating to theembodiment of the present invention.

FIG. 12A is a partially cut-away front elevation view showing a guidancestate of the recording tape cartridge relating to the embodiment of thepresent invention in the bucket, which shows a guidance state of thecase at which the slit is positioned at a vertical direction centralportion of a side wall.

FIG. 12B is a partially cut-away front elevation view showing a guidancestate of a recording tape cartridge relating to the embodiment of thepresent invention in a bucket, which shows a guidance state of a case atwhich a slit is positioned upward of a vertical direction centralportion of a side wall.

FIG. 13 is a perspective view showing overall structure of aconventional recording tape cartridge.

FIG. 14 is a perspective view showing overall structure of anotherconventional recording tape cartridge.

FIG. 15 is a perspective view showing overall structure of yet anotherconventional recording tape cartridge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A recording tape cartridge 10 relating to an embodiment of the presentinvention will be explained based on FIGS. 1 to 7C. Firstly, generaloverall structure of the recording tape cartridge 10 will be explained.Then, principal elements of the present invention, an opening 20 and adoor 50 which serves as a covering member for opening and closing theopening 20, will be explained. Further, a bucket 60 of a drive devicerelating to the embodiment of the present invention will be explainedthereafter. For the sake of convenience of explanation, a loadingdirection of the recording tape cartridge 10 into a drive device, whichis shown as arrow A, is referred to as a forward direction (front side)of the recording tape cartridge 10, and the direction of an arrow Bintersecting arrow A is a rightward direction.

[Overall Structure Of Recording Tape Cartridge]

FIG. 1 shows a perspective view of overall structure of the recordingtape cartridge 10. FIG. 2 shows a schematic exploded perspective view ofthe recording tape cartridge 10.

As shown in these drawings, the recording tape cartridge 10 isstructured to rotatably accommodate a single reel 14 in a case 12. Thecase 12 is substantially rectangular in plan view. A magnetic tape T iswound onto the reel 14. The magnetic tape T serves as a recording tapewhich is an information recording/replaying (reading/writing) medium.

The case 12 is structured by matching up and joining two peripheralwalls 16A and 18A of an upper case 16 and a lower case 18 to oneanother. A front-right corner portion of each of the upper case 16 andthe lower case 18, which is a single corner portion at a front end sidein the direction of loading into the drive device, is cut away. Anaccommodation space for the reel 14, onto which the magnetic tape T iswound, is provided inside the case 12. Hence, the cut away cornerportions of the peripheral walls 16A and 18A of the upper case 16 andthe lower case 18 serve as the opening 20 for drawing out the magnetictape T.

A leader pin 22 is connected at a free end of the magnetic tape T thatis drawn out through the opening 20. The leader pin 22 is caught up(engaged) by drawing-out means of the drive device, and subjected to adrawing-out operation. At each of two end portions of the leader pin 22,which protrude beyond width direction end portions of the magnetic tapeT, an annular groove 22A is formed. These annular grooves 22A are caughton to by hooks or the like of the drawing-out means. Consequently, inthis structure, the hooks or the like do not contact and damage themagnetic tape T when the magnetic tape T is drawn out.

At an inner side of the opening 20 of the case 12, a pair of upper andlower pin stands 24 are provided for positioning and retaining theleader pin 22 in the case 12. The pin stands 24 have semi-tubular forms,and both the end portions of the leader pin 22 are held at recessportions 24A of the pin stands 24 in a state in which the leader pin 22is standing thereat. Outer peripheral walls of the pin stands 24 areopen at a magnetic tape T drawing-out side thereof, to form exit/entryapertures through which the leader pin 22 is removed and inserted.

A leaf spring 25 is fixedly disposed in a vicinity of the pin stands 24.The leaf spring 25 engages with upper and lower end portions of theleader pin 22, and holds the leader pin 22 at the pin stands 24. Theleaf spring 25 is structured to resiliently deform appropriately whenthe leader pin 22 is removed or inserted at the pin stands 24, and toallow movements of the leader pin 22.

A gear aperture 26 is formed at a central portion of the lower case 18.The gear aperture 26 is for exposing an unillustrated reel gear of thereel 14 to the outside. The reel gear meshes with a driving gear of thedrive device, and the reel 14 is driven to rotate inside the case 12.Further, the reel 14 is held by free play-restricting walls 28 so as notto rattle about. The free play-restricting walls 28 are providedprojecting at interior surfaces of the upper case 16 and the lower case18, to serve as interior walls partially disposed along a circular pathwhich is coaxial with the gear aperture 26.

A hollow portion 28A is provided continuously with an end portion of thefree play-restricting walls 28 in a vicinity of the opening 20. A holefor regulation of position at an interior is formed in the hollowportion 28A. In addition, a hollow portion 28B is formed continuouslywith the free play-restricting walls 28 at an inner side of a front-leftcorner portion of the case 12. Another hole for regulation of position,which is a long hole, is formed in the hollow portion 28B. The hollowportion 28A and the hollow portion 28B are disposed co-linearly alongthe direction of arrow B.

Except for the end portion at which the hollow portion 28A iscontinuously provided, each of the free play-restricting walls 28 isprovided continuously with the peripheral wall 16A or the peripheralwall 18A of the case 12. Thus, outer sides of the free play-restrictingwalls 28 and the space for disposing the reel 14 are set apart.

[Structure of Opening and of Case at Opening Vicinity]

As described above, the opening 20 is formed by cutting away thefront-right corner portion. Therefore, an opening face thereof (anangled wall portion) faces in the direction of arrow A and in thedirection of arrow B. Consequently, the drawing-out means of the drivedevice can access and chuck the leader pin 22 from the direction ofarrow A, from the direction of arrow B, or from a direction between thedirections of arrow A and arrow B.

As a result, an area in which the pin stands 24 that hold the leader pin22 can be disposed is large, and a range from which the drawing-outmeans of the drive device can chuck the leader pin 22 is wide.Accordingly, a disposition position of the pin stands 24 can bespecified to meet specifications of drive devices that carry outchucking from direction A and drive devices that carry out chucking fromdirection B. Thus, a degree of freedom of design of the drive device isbroadened.

As is also shown in FIG. 3, which is a plan view of the lower case 18, apair of short upper and lower diagonal wall portions 30 is provided at aright corner portion of a front wall 12A of the case 12 (a portion ofthe peripheral walls 16A and 18A whose outer surface faces in thedirection of arrow A). The diagonal wall portions 30 define a front edgeportion of the opening 20. The diagonal wall portions 30 curve to runalong the opening face of the opening 20, and a wall thickness of thediagonal wall portions 30 is thicker than the front wall 12A.

A recess portion 30A is formed at a thickness direction central portionof the diagonal wall portions 30. A distal end of the door 50, which isdescribed later, enters into the recess portion 30A. Further, a pair ofupper and lower screw bosses 32 are provided continuously with an innerside of the front wall 12A in a vicinity of a left end of the diagonalwall portions 30.

A pair of upper and lower offset wall portions 34 is provided at a frontend portion of a right wall 12B of the case 12 (a right side wall of theperipheral walls 16A and 18A along the direction of arrow A). The offsetwall portions 34 are slightly offset to the inside of the case 12(leftward). Front ends of the offset wall portions 34 define a rear edgeof the opening 20.

A pair of upper and lower screw bosses 36 is provided continuously withan inner side of front end portions of the offset wall portions 34.Outer peripheral portions of the screw bosses 36 function as a guide forthe door 50 which is slidable against the door 50 (to prevent rattling).Further, a pair of upper and lower step portions 38 is integrally formedbetween rear end portions of the offset wall portions 34 and the rightwall 12B.

As shown in FIG. 4A, a slit 40 is provided in the right wall 12B,rearward of the offset wall portions 34. The slit 40 has a predeterminedlength and serves as a window portion which communicates between theinterior and exterior of the case 12. The slit 40 is for exposing anoperation projection 52 of the later-described door 50. The slit 40 isformed by cutting away a lower portion of the peripheral wall 16A thatstructures the right wall 12B and an upper portion of the peripheralwall 18A that structures the right wall 12B. A lower portion of theupper step portion 38 and an upper portion of the lower step portion 38are also cut away. Thus, the slit 40 also opens forward (to a side ofloading into the bucket 60 of the drive device). Consequently, anengaging protrusion 68 of the bucket 60 can be advanced into the slit 40from the front side. In the present invention, the right wall 12Bprovided with the slit 40 corresponds to a “side wall along a loadingdirection of the case into the drive device”.

The slit 40 may instead be defined from above and below simply by aceiling plate and a floor plate of the case 12, as in the variantexample shown in FIG. 4B. However, in view of strength when dropped, itis more preferable if portions of the upper case 16 and lower case 18are left above and below the slit 40 as described above, to function asribs such that rigidity is maintained. In particular, the peripheralwalls 16A and 18A, which join the upper and lower walls that define theslit 40 to one another at both ends of the slit, are formed integrally(provided continuously) with the offset wall portions 34 (the stepportions 38), which is even more preferable.

The slit 40 may be provided continuously with the opening 20 so as toopen frontward, with the offset wall portions 34 not being provided, asin the variant example shown in FIG. 4C. However, providing the opening20 and the slit 40 non-continuously as described above increasesrigidity of a rear edge corner portion of the opening 20, and ispreferable in view of strength when dropped. Furthermore, in thestructure of FIG. 4A, the screw bosses 36, which are slidable againstthe door 50, are provided spanning the whole height of the interior ofthe case 12, and a protrusion portion 42 (the offset wall portions 34)is provided. This is preferable in view of dustproofing.

The protrusion portion 42 protrudes from rear end portions of the upperand lower offset wall portions 34, at a side thereof which is oppositeto a side thereof at which the step portions 38 are disposed (that is,inward of the case 12) and is provided to span the whole height of theoffset wall portions 34. A distal surface of the protrusion portion 42is curved to correspond to an outer surface of the later-described door50. In addition, a protrusion portion 44 spanning the whole height isprovided at a location of the free play-restricting walls 28 whichcorresponds to the protrusion portion 42. The protrusion portion 44 iscurved to correspond with an inner face of the door 50, and opposes theprotrusion portion 42.

When the door 50 opens or closes the opening 20, the protrusion portion42 and the protrusion portion 44 are slidable against the door 50 whilesandwiching the door 50. Thus, the protrusion portion 42 and theprotrusion portion 44 are for preventing the ingression of dust into thecase 12, and are for guiding the door 50 (preventing looseness).

A further protrusion portion 46 protrudes inward of the case 12 at aportion of the right wall 12B (the peripheral walls 16A and 18A) thatdefines a rear end of the slit 40. The protrusion portion 46 is also forpreventing the ingression of dust into the case 12 and guiding the door50 (preventing rattling).

A recess portion 48 is formed rearward of the protrusion portion 46 ofthe lower case 18. The recess portion 48 is recessed toward the insideof the case 12 at a portion of the peripheral wall 18A, which does notinclude an upper end of the peripheral wall 18A, and upward from a lowerface of the case 12, and substantially has a three-sided box shape insectional view. The recess portion 48 is also formed in a left wall ofthe case 12. These recess portions 48 serve as, for example, engagingportions for engaging with the drawing-out means of the drive device,with bottom surfaces of the recess portions 48 (surfaces that facedownward) serving as reference surfaces for positioning in the drivedevice. Furthermore, twisting strength of the case 12 is improved byprovision of the recess portions 48.

A portion of the right wall 12B (the peripheral wall 18A) that definesthe recess portion 48 is curved to correspond to the outer surface ofthe door 50. This guide surface 48A serves as a guide for the door 50,and is slideable against the outer surface of the door 50 when theopening 20 is opening or closing (to prevent looseness).

The upper case 16 and the lower case 18 described above are fixed(joined) by unillustrated screws which are screwed from the lower sideinto each of the screw bosses 32 and 36 (joining portions), which arelocated in the vicinities of edge portions of the opening 20.Accordingly, corner portions at both ends of the opening 20, which aredefined by free ends of the diagonal wall portions 30 (the front wall12A) and the offset wall portions 34 (the right wall 12B) and which tendto be severely affected when impacted against a floor or the like by afall, are securely fixed. Thus, even if the case 12 is dropped, thisstructure will not be deformed or buckled by the overall weight of therecording tape cartridge 10, so as to cause mispositioning.

A major diameter across the threads of the screws may be, for example,2.0 mm. Thus, an external diameter of the screw bosses 32 and the screwbosses 36 may be 4.0 mm. In place of this fixing with screws,projections may project from the upper case 16 at positionscorresponding to the screw bosses 32 and 36, while fitting holes whichfit with these projections are formed in the lower case 18, and theprojections and fitting holes may be fitted with one another. However,in such a case, it is desirable that the upper case 16 and the lowercase 18 be fixed with screws at locations within radii of 30 mm of thesefitting locations. Further, matching surfaces of the peripheral wall 16Aand the peripheral wall 18A (at both side corner portions of the opening20) may be fixed by welding. However, fixing with screws is morepreferable in consideration of dismantling and recycling.

Plate thicknesses of both the upper case 16 and the lower case 18 areset to 2 mm at the area in which the pin stands 24 are disposed (thevicinity of the opening 20), which is thicker than thicknesses at otherareas thereof. The case 12 (the upper case 16 and the lower case 18) isformed of a polycarbonate (PC) material. The case 12 may be formed ofacrilonitrile butadiene styrene (ABS) or a metal instead of PC.

The purpose of this is to raise the strength of the vicinity of the pinstands 24, which is the location at which the leader pin 22 is held(positioned). Therefore, mispositioning of the leader pin 22, which isthe most important component for functioning of the recording tapecartridge 10 (and which must be accurately engaged by the drawing-outmeans when the recording tape is to be drawn out), subsequent to impactsdue to dropping of the case 12 (the recording tape cartridge 10) or thelike does not occur.

Positions at which the pin stands 24 are disposed are determined suchthat an axial center of the leader pin 22 held thereat is positioned ona first imaginary line (not illustrated), which joins the front and rearedge portions of the opening 20, or further inside the case 12 than thefirst imaginary line. The positions at which the pin stands 24 aredisposed are more preferably determined such that the axial center ofthe leader pin 22 is positioned on a second imaginary line (also notillustrated), which joins axial centers of the screw bosses 32 and thescrew bosses 36, or further inside the case 12 than the second imaginaryline. In the present embodiment, the pin stands 24 are disposed at aposition closer to the screw bosses 32 than to the screw bosses 36.Thus, with this structure, mispositioning of the leader pin 22 due tovibrations of the ceiling plate and the floor plate that accompanydropping of the case 12 or the like can be prevented.

In this case 12, the peripheral wall 16A of the upper case 16 and theperipheral wall 18A of the lower case 18 are set to equal heights. Thus,machining accuracies of portions thereof that match up with one another(accuracies of resin-forming in molds) are at about the same level.Thus, assembly characteristics and dropping impact resistance are madefavorable.

A diagonal angle of the opening face of the opening 20 with respect tothe direction of arrow A (a diagonal angle of the ceiling plate andfloor plate of the case 12 that define the top and bottom of the opening20) is determined in accordance with requirements for distinguishing(identifying) the recording tape cartridge 10 at a library apparatus.That is, the library apparatus accommodates a plurality of the recordingtape cartridge 10 and automatically (i.e., without human intermediation)mounts and removes the recording tape cartridge 10 at the drive device.In a case where there is a plurality of types of the recording tapecartridge 10 to be handled and a plurality of types of drive device, itis necessary to identify a generation, recording capacity or the like ofthe recording tape cartridge 10. The diagonal angle of the opening faceof the opening 20 may be utilized for this identification.

Accordingly, the opening 20 for drawing out of the magnetic tape T,which has been implemented in consideration of strength as describedabove, can also function as an identification portion in a libraryapparatus, based on the diagonal angle of the opening face of theopening 20 (to be specific, the diagonal angle of the ceiling plate andfloor plate that define the top and bottom of the opening 20).Therefore, insufficient strength of the case 12, a deterioration ofdustproofing and complicated mold construction, which are concerns in asituation in which the opening 20 and the identification portion areprovided separately (for example, a case in which one or a plurality ofthrough-holes formed in the case 12 serve as an identification portion),can be prevented.

[Door Structure]

As shown in FIGS. 5 and 6, which are viewed with the reel 14, the uppercase 16 and the like removed, the opening 20 is opened and closed by thedoor 50, which serves as a covering member. The door 50 is formed in acircular arc form in plan view, which is curved in a plate thicknessdirection along a predetermined circular circumference, with a platewidth (height) of the door 50 set to be substantially the same as anopening height of the opening 20, and a plate length thereof beingsignificantly greater than an opening width of the opening 20.

Specifically, in this structure, in a state in which the door 50 hasentered into the recess portion 30A of the diagonal wall portions 30 (aclosed position), the door 50 closes the opening 20 (see FIG. 7A). Thedoor 50 opens the opening 20 by moving (rotating) substantially rearwardalong the aforementioned circular circumference, (see FIG. 7B). When anouter peripheral surface of a distal end vicinity of the door 50 reachesa vicinity of the screw bosses 36, the opening 20 is completely opened(an open position; see FIG. 7C). When the opening 20 is open, the door50 closes the opening 20 by rotating substantially in the oppositedirection. In the closed state of the opening 20, the door 50 abutsagainst at least one of the screw bosses 36, the protrusion portion 42and the protrusion portion 44.

That is, the door 50 is formed to be curved in an arc shapecorresponding to the predetermined circular circumference, which is amovement path of the door 50. In the present embodiment, a position of acenter of rotation of the door 50 in a left-right direction is specifiedto be at a left end vicinity of the case 12, and a position thereof in afront-rear direction is specified to be at a vicinity of the rear end ofthe slit 40. Consequently, the movement path of the door 50 is closestto the right wall 12B of the case 12 in the vicinity of the rear end ofthe slit 40. The rotation center and a turning radius of the door 50 maybe suitably determined in accordance with the positions of the front andrear edge portions of the opening 20 (the diagonal wall portions 30 andthe screw bosses 36). These positions are determined by requirements ofthe drive device, in accordance with the angle of the facing surface ofthe opening 20, which is determined by requirements of a libraryapparatus, and the like.

A rear end portion of a length dimension along the curve of the door 50is determined so as to be located at a rear-right corner portion, whichis rearward of the recess portion 48 of the case 12, in the state inwhich the opening 20 is closed. Accordingly, all through the process ofopening and closing the opening 20, the door 50 is guided (loosenessthereof is restrained) by the screw bosses 36, the protrusion portions42, 44 and 46, and the guide surface 48A (and the free play-restrictingwalls 28) of the case 12.

At an outer peripheral surface of the door 50, slightly forward from alength direction central portion thereof, the operation projection 52projects along a diametric direction of the door 50, to serve as anoperation portion. The operation projection 52 is exposed to the outsideof the case 12 through the slit 40. When the opening 20 is in the closedstate, the operation projection 52 is positioned to be slightlyseparated from the protrusion portion 42 at the rear end of the offsetwall portions 34, and is operable through the portion of the slit 40that opens frontward at the step portions 38. Dimensions of each portionare determined such that a distal end portion of the operationprojection 52 does not protrude further than the outer surface of theright wall 12B (an exterior profile of the case 12) in this state (seeFIGS. 5 and 7A).

When the opening 20 is in the opened state, the operation projection 52is positioned to be slightly separated from the protrusion portion 46 atthe rear edge of the slit 40. The dimensions of each portion aredetermined such that a length direction of the operation projection 52is substantially perpendicular to the right wall 12B of the case 12 (thedirection of arrow A) in this state (see FIG. 7C).

Thus, although this operation projection 52 communicates between theinterior and exterior of the case 12 via the slit for exposure, the slit40 is always substantially closed by the door 50, which spanssubstantially the whole height of the interior of the case 12, and bythe protrusion portion 42 and protrusion portion 46 which guide the door50. In addition, a labyrinthine structure is formed between the slit 40and the accommodation space for the reel 14 by the free play-restrictingwalls 28 which serve as inner walls and the protrusion portion 44 whichguides the door 50. Accordingly, adherence of dust and the like to themagnetic tape T wound onto the reel 14 is prevented.

A spring-holding portion 54 protrudes along the diametric direction ofthe door 50 from an interior peripheral portion at a rear end vicinityof the door 50. One end portion of a coil spring 56, which serves asurging means (an urging element), is engaged with a spring-engagingportion 55, which is provided inside the case 12 at a vicinity of therecess portion 48. Another end portion of the coil spring 56 is engagedand held at the spring-holding portion 54. Accordingly, in thisstructure, the door 50 is urged in a direction to close the opening 20by urging force of the coil spring 56, and the door 50 continuouslycloses the opening 20.

The coil spring 56 has a length that reaches as far as the rear-rightcorner portion of the case 12 in the state in which the door 50 opensthe opening 20 as described above. Thus, the coil spring 56 is disposedso as to effectively use a space between the free play-restricting walls28 and the peripheral walls 16A and 18A at the rear-right cornerportion. In the present embodiment, the coil spring 56 is a tension coilspring, and the coil spring 56 is disposed between the door 50 and thefree play-restricting walls 28 (at the inner peripheral side of the door50) so as not to interfere with the movement path of the door 50, whichhas the circular arc form in plan view (see FIGS. 7A to 7C).

The coil spring 56, which urges the plan view circular arc-form door 50substantially forward at a rear side relative to the center of rotationof the door 50 along the front-rear direction, is disposed such that alongitudinal direction (urging direction) thereof is at an angle withrespect to the right wall 12B of the case 12 (that is, with respect tothe direction of arrow A). Therefore, an urging force F acts on the door50 as shown in FIG. 5. The door 50 is urged in the direction to closethe opening 20 by a force component F1 of the force F, which acts in thedirection of arrow A, and the door 50 is urged toward the right wall 12Bside thereof by a force component F2 of the force F, which acts in thedirection of arrow B.

The door 50 is thus positioned by the force component F2 such that adistal end of the operation projection 52 is substantially coplanar withthe outer surface of the right wall 12B (that is, in a range such thatthe operation projection 52 does not protrude from the outer surface ofthe right wall 12B, as mentioned above). Consequently, the door 50 isstructured to be capable of assuring an engagement amount of theoperation projection 52 with respect to the engaging protrusion 68,which advances in through the front side opening end of the slit 40formed in the right wall 12B. That is, although there is clearance inthe diametric direction (substantially the left-right direction) betweenthe door 50 and the screw bosses 36, the protrusion portions 42, 44 and46 and the like, which are guide means for enabling movement of the door50, because the door 50 is urged to the right wall 12B side by the forcecomponent F2, the door 50 is located at a suitable position to enableassurance of the engaging amount of the operation projection 52 with theengaging protrusion 68.

The door 50 described hereinabove is formed of, for example, apolyoxymethylene (POM) resin, which has a low coefficient of frictionand has excellent abrasion resistance with respect to the case 12constituted of PC. The operation projection 52, the spring-holdingportion 54 and the like may be structured as separate bodies (ofdifferent materials). Thus, because operation of the door 50 can becarried out smoothly, it is preferable if clearances between endsurfaces at the top and bottom of the door 50 and the ceiling plate andfloor plate of the 12 are set to the order of 0.05 mm to 0.2 mm each.

[Structure Of Drive Device Bucket]

Next, the bucket 60 of a drive device at which a recording tapecartridge having the structure described above is loaded will beexplained. The drive device is an apparatus which draws out the leaderpin 22 from the opening 20 of the recording tape cartridge 10 that hasbeen loaded into the bucket 60, draws the leader pin 22 to a windingreel, and retains the leader pin 22 at the winding reel. The drivedevice rotates this winding reel and the reel 14 contemporaneously and,using a recording/replaying head which is disposed along a predeterminedtape path, carries out recording of information onto the magnetic tape Tand/or replaying of information that has been recorded on the magnetictape T (the head may be provided only with one of the recording functionand the replaying function).

FIG. 8 shows a perspective view, viewed from below, of the bucket 60. Asis shown in this drawing, a right guide wall 62 and a left guide wall 64are provided, which each serves as a guide wall having length along thedirection of arrow A. Respective upper end portions of the right guidewall 62 and the left guide wall 64 are joined by a ceiling plate portion66. Stoppers 66A, which regulate a loading (insertion) depth of the case12, are provided extending downward at a front end of the ceiling plateportion 66.

An opposing distance between the right guide wall 62 and the left guidewall 64 corresponds to a left-right width of the case 12. Accordingly,the right guide wall 62 slides against the right wall 12B of the case 12that is loaded, and guides the same, while the left guide wall 64 slidesagainst a left wall 12C, which is opposite from the right wall 12B (seeFIGS. 1 and 2), and guides the same.

Lower end portions of the right guide wall 62 and the left guide wall 64are respectively curved, to form bottom plate portions 62A and 64A whichoppose the ceiling plate portion 66. The case 12 that is loaded into thebucket 60 is placed on the bottom plate portions 62A and 64A.

The engaging protrusion 68, which serves as an opening member, isprovided to protrude leftward at a length direction intermediate portionof the right guide wall 62. The engaging protrusion 68 is disposed so asto be engageable with the operation projection 52 of the recording tapecartridge 10. With the structure as shown in FIGS. 7A to 7C, theengaging protrusion 68 engages with the operation projection 52 inaccordance with an operation of loading the recording tape cartridge 10into the bucket 60, and moves the door 50 in the direction of openingthe opening 20 (an open position direction).

A let-out hole 69, which serves as an overflow portion, is formedrearward of the engaging protrusion 68 (i.e., at a side thereof thatengages with the operation projection 52) at the right guide wall 62.This let-out hole 69 is entered into by the operation projection 52,which projects to an outer side from the outer surface of the right wall12B in accordance with opening of the opening 20, as shown in FIGS. 7Band 7C.

Accordingly, the right guide wall 62 is capable of sliding against andguiding the right wall 12B as described above. Consequently, when thefront wall 12A of the case 12 abuts against the stoppers 66A, theengaging protrusion 68 is disposed such that the opening 20 iscompletely open, as shown in FIG. 7C.

Unillustrated holding means, which holds the case 12 in the state shownin FIG. 7C, is provided at the bucket 60. Consequently, the recordingtape cartridge 10 is not ejected from the bucket 60 by the urging forceof the coil spring 56.

In the present embodiment, the engaging protrusion 68 and the let-outhole 69 are formed adjacently to one another in a simple construction bybending a portion which is left uncut when a substantial U-shape, whichopens toward the front side, is cut out from the right guide wall 62. Inthe present embodiment, dimensions of each portion are determined suchthat the operation projection 52 will not project to an outer side ofthe right guide wall 62 in the state shown in FIG. 7C. A depression maybe provided instead of the let-out hole 69.

When the recording tape cartridge 10 is loaded in the bucket 60described above and the stoppers 66A abut against the front wall 12A,the bucket 60 descends together with the recording tape cartridge 10that is in the drive device, and the bucket 60 positions the recordingtape cartridge 10 and meshes the reel gear of the reel 14 with thedriving gear of the drive device.

Next, operation of the present embodiment will be described.

In the recording tape cartridge 10 having the structure described above,the opening 20 is closed by the door 50 when the recording tapecartridge 10 is not in use (during storage, during transportation, andthe like). Specifically, a distal end portion (front end portion) of thedoor 50 is entered into the recess portion 30A of the diagonal wallportions 30 by the urging force (force component F1) of the coil spring56. At the same time, an intermediate portion outer peripheral surfaceof the door 50 abuts against the outer peripheral surface of the screwbosses 36 to close the opening 20. Further, in this state, the door 50is urged to the right wall 12B side by the urging force (force componentF2) of the coil spring 56, and the operation projection 52 of the door50, being substantially coplanar with the right wall 12B, is exposedthrough the slit 40.

In contrast, when the magnetic tape T is to be used, the recording tapecartridge 10 is loaded into the bucket 60 of the drive device along thedirection of arrow A. In accordance with this loading, the right guidewall 62 and the left guide wall 64 guide the right wall 12B and leftwall 12C, respectively, of the case 12, while moving along a directionopposite to the direction of arrow A relative to the case 12. Thus, asshown in FIG. 7A, the engaging protrusion 68, which serves as theopening member structuring opening means of the drive device, advancesinto the slit 40 which opens frontward at the step portions 38, andengages with the operation projection 52 of the door 50.

As the recording tape cartridge 10 (the case 12) is pushed in further,the urging force of the coil spring 56 is opposed by a force of pushingin and, as shown in FIG. 7B, the engaging protrusion 68 moves theoperation projection 52 rearward (that is, relatively rearward withrespect to the case 12 which is being loaded in the direction of arrowA). At this time, the operation projection 52 projects beyond the outersurface of the right wall 12B and enters into the let-out hole 69 of thebucket 60. Accordingly, a state of guiding of the case 12 by the rightguide wall 62 and the left guide wall 64 is maintained.

Thus, the door 50 from which the operation projection 52 protrudes isguided by the screw bosses 36, the protrusion portions 42, 44 and 46,and the guide surface 48A. At the same time, the door 50 rotatesclockwise, in plan view, along the direction of curvature thereof. Thatis, the door 50 moves substantially rearward so as to swing at the outerside of the reel 14 and the pin stands 24 without significantlydeviating from the movement path along the shape of the curvature, andthe door 50 opens the opening 20.

Thus, when the case 12 (the recording tape cartridge 10) is loaded to apredetermined depth in the drive device, the opening 20 is completelyopen, as shown in FIG. 7C. In this state, the holding means holds thecase 12 and maintains the opened state of the opening 20. Hence, thebucket 60 descends in the drive device from this state, the case 12 ispositioned with respect to the drive device in accordance with thisdescent, and the reel gear of the reel 14 is meshed with the drivinggear.

In this state, the drawing-out means of the drive device advances intothe case 12 through the opened opening 20, and the drawing-out meanstakes out the leader pin 22, which has been positioned and accommodatedat the pin stands 24, and accommodates the leader pin 22 at the windingreel. Then, the winding reel and the reel 14 are driven to rotate at thesame time, and the magnetic tape T is wound around the winding reelwhile being sequentially drawn out from the case 12. Informationrecording/replaying is carried out on the magnetic tape T by therecording/replaying head or the like which is disposed along thepredetermined tape path.

Subsequently, when the magnetic tape T has been wound back to the reel14 again, the bucket 60 rises in the drive device, and releases both thestate of positioning of the recording tape cartridge 10 and the state ofmeshing of the reel gear of the reel 14 with the driving gear. Then, theholding means of the bucket 60 releases the state of holding the case12, the recording tape cartridge 10 is moved in a direction opposite tothe direction of arrow A by the urging force of the coil spring 56and/or by an unillustrated ejection mechanism, and the recording tapecartridge 10 is ejected from the bucket 60.

In accordance with this ejection operation, the door 50 is guided by thescrew bosses 36, the protrusion portions 42, 44 and 46, and the guidesurface 48A, while being rotated in the closing direction of the opening20 by the urging force of the coil spring 56. The distal end portion ofthe door 50 enters into the recess portion 30A of the diagonal wallportions 30, and the door 50 returns to the initial state in which theopening 20 is completely closed.

Here, because the opening 20 is formed by cutting away the loading sidecorner portion of the rectangular case 12, the opening face of theopening 20 faces in the direction of arrow A and in the direction ofarrow B (the facing angle is diagonal with respect to the direction ofarrow A). This means that the drawing-out means of the drive device cangain access to the leader pin 22 from a front face side which faces thecase 12 in the direction of arrow A, and it is not required that thedrawing-out means gain access from a side that is outside of the arrow Bside peripheral walls (side walls) 16A and 18A (i.e., from an arrow Bside).

Consequently, in this drive device, a path for drawing out the magnetictape T can be made as short as possible, and the drawing-out means doesnot require a drive mechanism for turning the magnetic tape T aroundfrom the arrow B side of the case 12. Thus, a reduction in size and costreductions can be expected.

Further, the door 50, which is curvedly formed in the circular arcshape, is rotated to open and close the opening 20 by swinging around anouter side of the reel 14 and the pin stands 24 (and the leader pin 22)without deviating from the movement path along the shape of thecurvature. Therefore, the door 50 will not protrude beyond an externalprofile region of the case 12 during opening and closing of the opening20.

Consequently, a space for accommodation of the recording tape cartridge10 in the drive device is small, and the movement path of the door 50does not interfere with the pin stands 24 (the leader pin 22), the reel14 and the like in the case 12.

Further yet, because the door 50 moves substantially in the front-reardirection at the inner side of the right wall 12B, which runs along thedirection of arrow A, for opening and closing the opening 20, it issufficient that the engaging protrusion 68 of the drive device befixedly disposed to be engageable with the operation projection 52 ofthe door 50 simply by advancing into the slit 40 from the front sidethereof. Thus, construction is simple.

Further again, because the door 50 closes the opening 20 due to theurging force of the coil spring 56, a drive device side mechanism fordriving the door 50 in the direction of closing the opening 20 (a closedposition direction) is not required. Thus, construction of the openingmeans (opening member) of the drive device is made more simple.Moreover, because the operation projection 52 of the door 50 is disposedso as to be substantially coplanar with the outer surface of the rightwall 12B, due to the urging force of the coil spring 56 (force componentF2), in the closed state of the opening 20, a predetermined engagementamount of the operation projection 52 with the engaging protrusion 68 isassured. Thus, the opening 20 is reliably opened by the opening means(the engaging protrusion 68), whose construction is simple, inaccordance with the operation of loading the recording tape cartridge 10into the drive device. During the process of opening the opening 20, aforce component based on the urging force of the coil spring 56, whichcorresponds to the force component F2, acts on the door 50. Thus, theoperation projection 52 and the engaging protrusion 68 can be moreassuredly engaged than in a case in which this force component does notact.

Accordingly, with the recording tape cartridge 10 relating to thepresent embodiment, the door 50, which can make a space foraccommodating the recording tape cartridge 10 at the drive devicesmaller, can open and close the opening 20, whose structure can minimizelength of the drawing-out path of the magnetic tape T, without the door50 interfering with the reel 14 and the leader pin 22. Moreover, theengaging protrusion 68, which serves as the opening means (openingmember) for operating the door 50 to open and close the opening 20, canbe given a simple structure.

Because the movement path of the door 50 as described above is acircular circumference (a curvilinear shape), the corner portion of thecase 12 can be greatly cut away, and the opening 20 can be formed to belarge. That is, in a case in which, for example, a flat plate-formcovering member is inclined relative to the direction of arrow A, thiscovering member will be accommodated in an exterior profile region ofthe case 12. In this situation, an operation area that is required forchanging the attitude of the covering member by linear displacement orrotary displacement to open and close the opening 20 will be greater,and the opening 20 will have to be made smaller (the cutaway portion ofthe corner portion of the case 12 that forms the opening 20 will have tobe made smaller) such that the operation of the covering member does notinterfere with the leader pin 22, the reel 14 and the like. However,with the recording tape cartridge 10 relating to the present embodiment,because the door 50 which opens and closes the opening 20 by turning onthe predetermined circular arc without deviating therefrom as describedabove is provided, an increase in size of the opening 20 can be enabled.

In particular, a center of rotation of the door 50 for opening andclosing the opening 20, whose opening face is diagonal with respect tothe direction of arrow A, can be determined independently of theposition of an axial center of the reel 14. Therefore, the angle ofinclination of the opening face of the opening 20 relative to thedirection of arrow A, the size of the opening 20 (a separation betweenfront and rear edge portions thereof, and the like can be freelyspecified. Thus, the door 50 can be provided for opening and closing theopening 20, with the opening 20 having dimensions and shape freelyselected in accordance with requirements of the drive device and thelike. That is, with the structure in which the door 50 is provided, adegree of freedom of design of the opening 20 (and thus the recordingtape cartridge 10) is improved.

Further, when the length of the path for drawing out the magnetic tape Tis minimized as described above, a running path of the magnetic tape Twill inevitably be shortened too. As a result, contact friction of themagnetic tape T with tape guides (for example, rotatably supportedrollers and the like) can be reduced.

Furthermore, the opening 20 is formed by cutting away the corner portionof the case 12, and faces in the direction of arrow A and in thedirection of arrow B. Thus, a range of directions of access to theleader pin 22 by the drawing-out means (by hooks thereof or the like) iswidened. Therefore, positions at which the leader pin 22 can be disposedin the case 12 are broadened. Therefore, given that the operation pathof the door 50 as described above must not interfere with positions atwhich the leader pin 22 can be disposed in practice, a degree of freedomof design of the drive device is improved.

Further again, because the door 50 is a separate member from the leaderpin 22 that is drawn out from the case 12, in this structure the door 50cannot be taken out from the case 12 in an assembled state. Thus, thedoor 50 will not be removed from the case 12 by an impact when therecording tape cartridge 10 is dropped or the like. Moreover, the leaderpin 22 is accommodated in the case 12 in a firmly shut state when theopening 20 has been closed by the door 50 at a time of non-use. Thus,the leader pin 22 is less likely to become damaged or soiled.Consequently, drawing out and running the magnetic tape T at the drivedevice will not affect the drive device, and the magnetic tape T itselfwill not suffer from damage.

Meanwhile, at the drive device, the let-out hole 69 is provided in theright guide wall 62 of the bucket 60 at which the recording tapecartridge 10 is loaded, at the rear side (the side that engages with theoperation projection 52) of the engaging protrusion 68. Therefore, theoperation projection 52, which protrudes beyond the outer surface of theright wall 12B of the case 12 in accordance with opening of the opening20, can overflow into the let-out hole 69, and the right guide wall 62(and the left guide wall 64) can maintain the function of guiding thecase 12.

Specifically, the operation projection 52 of the door 50, which movesalong the predetermined circular arc in accordance with opening of theopening 20, has a movement path which is a circular circumference (acircular circumference with a greater diameter than that of the door50). In a structure in which the operation projection 52 is alwaysdisposed inside the case 12 so as to maintain the aforementioned guidingfunction, the case 12 (and the bucket 60 and the drive device) becomelarger. However, in the present drive device provided with the bucket60, the recording tape cartridge 10 and the bucket 60 (the drive deviceitself) can achieve the aforementioned guiding function without anincrease in size, by a simple construction which is simply provided withthe let-out hole 69. Consequently, looseness of the recording tapecartridge 10 in the bucket 60 is suppressed, and the engaging protrusion68 can reliably engage with the operation projection 52 and open theopening 20.

Accordingly, in the drive device relating to the present embodiment,which is provided with the bucket 60, the opening 20 of the recordingtape cartridge 10 can be reliably opened and closed. In addition, anincrease in size of the recording tape cartridge 10 and of the drivedevice itself (the bucket 60) can be averted.

In the embodiment described above, the door 50 is structured to beguided in a direction for opening or closing the opening 20 (that is, ina direction of rotation corresponding to the shape of curvature of thedoor 50) by the screw bosses 36, the protrusion portions 42, 44 and 46,and the guide surface 48A. However, the present invention is not limitedthus. For example, the door 50 may have a structure relating to avariant example, as shown in FIGS. 9 to 10C.

FIG. 9 shows a plan view, corresponding to FIG. 3, which shows the lowercase 18. As shown in this drawing, a guide channel 70, which correspondsto the movement path of the door 50, is formed in the lower case 18.Further, although not illustrated, another guide channel 70 is formed inthe upper case 16 in correspondence with the guide channel 70 of thelower case 18.

In consideration of strength of the case 12 when dropped, a front end ofthe guide channel 70 is leftward of the screw bosses 36. A rear end ofthe guide channel 70 is set to a position corresponding to a rear endportion of the door 50 in the opened state of the opening 20. Athickness of the case 12 at a channel bottom portion of the guidechannel 70 is set from 0.5 mm to 1 mm, in consideration of the droppingstrength.

As shown in FIGS. 10A to 10C, guide pins 72, which are plurallyprotruded (in the present embodiment, four above and four below) atsubstantially equal intervals along width direction (vertical direction)end faces of the door 50, are slideably inserted into the guide channels70. Of these guide pins 72, the forwardmost disposed guide pins 72 arepositioned at front end vicinities of the guide channels 70 when theopening 20 is in the closed state, and the guide pins 72 that aredisposed at a rear end portion of the door 50 are positioned at rear endvicinities of the guide channels 70 when the opening 20 is in the openedstate.

The respective guide pins 72 may be formed integrally with the door 50that is constituted of POM, and may be formed separately from a mainbody of the door 50. In the case of separate bodies, the guide pins 72may be structured of a resin such as polyamide (PA),polytetrafluoroethylene (PTFE), polyethylene (PE) or the like, ametallic material, or a material including one or more of these as aprincipal component. However, in a situation in which the case 12 isstructured of a metallic material, it is required that the guide pins 72be structured of a resin material, in consideration of abrasioncharacteristics, prevention of noise, and the like.

Clearances between the respective guide pins 72 and the guide channel 70(in a width direction of the guide channel 70) are preferably from about0.05 mm to 0.4 mm at each side, assuming that center lines of the guidepins 72 and the guide channel 70 coincide with one another (0.1 mm to0.8 mm for both sides). In particular, it is favorable if the clearanceat each side is set to 0.2 mm, such that wobbling of the door 50 can beprevented and movement can be smooth.

With a structure relating to the present variant example as shown inFIGS. 10A to 10C, when the opening 20 is opened or closed, the door 50is guided at the screw bosses 36, the protrusion portions 42, 44 and 46,and the guide surface 48A, the guide pins 72 are guided in the guidechannels 70, and the door 50 moves smoothly. Further, in this structuretoo, the door 50 is urged to the right wall 12B side (to outer sidechannel walls of the guide channels 70) by the force component F2 of theurging force of the coil spring 56. Thus, the operation projection 52reliably engages with the engaging protrusion 68 when the opening 20 isbeing opened.

In this structure provided with the guide channels 70, the door 50 maybe structured so as to not be guided at the screw bosses 36, theprotrusion portions 42, 44 and 46, and the guide surface 48A. However,in order to assure dustproofing, it is preferable that at least theprotrusion portion 42 and the protrusion portion 46 are provided.Further, in a case in which a spacing between neighboring the guide pins72 of the door 50 is greater than a movement (rotation) amount of thedoor 50, the guide channel 70 may be formed so as to be partitionedappropriately.

In the embodiment that has been described above, the slit 40 is formedby cutting away from both of the peripheral walls 16A and 18A thatstructure the right wall 12B. However, the present invention is notlimited thus. For example, a structure relating to a variant example asshown in FIG. 11 may be employed. A slit 74 shown in FIG. 11 isdifferent from the slit 40 in that the slit 74 is structured by cuttingaway only from the peripheral wall 16A that structures the right wall12B. This is described more specifically below.

The upper case 16 and the lower case 18 are provided with the peripheralwalls 16A and 18A, which structure the right wall 12B as far as avicinity of a rear edge portion of the opening 20. Front end portions ofthe peripheral walls 16A and 18A are curved to run along opening piecesof the opening 20, and serve as curved walls 76 which are continuouswith the screw bosses 36. At the upper case 16 and the lower case 18,diagonal wall portions 78 having a predetermined length are provided atthe inner side of the peripheral walls 16A and 18A that structure theright wall 12B, respectively, in place of the offset wall portions 34.

The upper and lower diagonal wall portions 78 are set at an anglerelative to the direction of arrow A, such that rear ends thereofapproach the right wall 12B. These rear ends serve as continuous walls78A, which are continuous with the peripheral wall 16A and theperipheral wall 18A, respectively. Front ends of the diagonal wallportions 78 are continuous with the screw bosses 36 (not shown).

The slit 74 is formed by cutting away a lower portion of the peripheralwall 16A that structures the right wall 12B, and is opened forward bycutting away a lower portion of the curved wall 76 of the upper case 16.That is, a lower end portion of the slit 74 is defined by upper endsurfaces of the peripheral wall 18A and curved wall 76 of the lower case18. Thus, the slit 40 is located upward of a matching-up portion of theupper case 16 and the lower case 18 (a parting line PL). Accordingly,the operation projection 52 of the door 50 is located at an upper siderelative to a vertical direction central portion of the door 50.

In this slit 74, when the opening 20 is in the closed state, theoperation projection 52 is located slightly apart from and rearward ofthe continuous walls 78A. In this state, as in the case of the slit 40,the operation projection 52 does not project beyond the outer surface ofthe right wall 12B. When the opening 20 is in the opened state, theoperation projection 52 is positioned to be slightly forward andseparated from a rear edge of the slit 74. In this state, the operationprojection 52 projects beyond the outer surface of the right wall 12B,in the same manner as in the case of the slit 40.

In the structure shown in FIG. 11, the guide channels 70 are providedextending as far as the recess portion 30A of the diagonal wall portions30, and channel walls that structure the guide channels 70 are providedcontinuously with the pin stands 24.

In a structure that is provided with this slit 74, because the slit 74is formed by cutting away only the peripheral wall 16A of the upper case16, looseness of the case 12 in the bucket 60 can be suppressed withouta step being formed in the longitudinal direction of the right wall 12B.

That is, the upper case 16 and the lower case 18 are generally formed byresin molding, and draft angles for die-cutting at the respectiveperipheral walls 16A and 18A are generally specified such thatmatching-up ends (opening ends) of the peripheral walls 16A and 18A arewidened. Thus, a left-right width of the case 12 is at a maximum at aposition of the parting line PL. Consequently, as shown in FIG. 12A,when the slit 40 is formed by cutting away from both the peripheral wall16A and the peripheral wall 18A, the left-right width of the case 12 issmaller at locations at which the slit 40 is disposed. Thus, becausethis slit 40 opens forward for allowing the engaging protrusion 68 toadvance thereinto from frontward thereof, that is, because theleft-right width of the case 12 is smaller at the front end portion ofthe right wall 12B, a gap G is generated between the case 12 and theright guide wall 62 and/or the left guide wall 64. This gap G is a causeof looseness of the case 12 in the bucket 60, which may lead to engagingfailures of the engaging protrusion 68 with the operation projection 52.Thus, failures of operation of the door 50 are a concern.

In contrast therewith, in a structure including the slit 74 as shown inFIG. 12B, because the slit 74 is formed by cutting away only theperipheral wall 16A of the upper case 16, the upper edge portion of theperipheral wall 18A of the lower case 18 coincides with the parting linePL, and the left-to-right width of the case 12 is constant along thewhole of the longitudinal direction of the right wall 12B, includingportions at which the slit 74 is formed (if machining errors and thelike are disregarded). Consequently, in the structure including the slit74, a gap that corresponds to the gap G is not formed, theaforementioned looseness is prevented, and failures of operation of thedoor 50 that are caused by the aforementioned looseness are prevented.

Further, as shown in FIG. 12B, if a distal end of the operationprojection 52 is angled in correspondence with the draft angle of theperipheral wall 16A, a surface area of engagement of the operationprojection 52 with the engaging protrusion 68 can be made greater.

In the same way as in the slit 40, upper and lower ends of the slit 74are defined by a portion of the peripheral wall 16A and by theperipheral wall 18A, which also function as ribs. Therefore, rigidity ofthe case 12 is maintained, which is preferable in view of droppingstrength. Moreover, the slit 74 is provided non-continuously with theopening 20, with the screw bosses 36 being disposed therebetween.Therefore, rigidity of the corner portion at the rear edge of theopening 20 is higher, which is further preferable in view of droppingstrength.

Of course, the slit 74 could be formed by cutting away from only theperipheral wall 18A of the lower case 18 structuring the right wall 12B.

The structure of the embodiment described above is a preferablestructure in which the door 50 rotates in the direction of opening theopening 20 when the operation projection 52, which is exposed to theoutside through the slit 40, engages with the engaging protrusion 68 ofthe drive device. However, the present invention is not limited thus.For example, a portion of the guide channel 70 in a range of operationof one of the guide pins 72 that is provided protruding downward at arear end portion of the door 50 could be made to serve as athrough-hole. The guide pin 72 that is exposed to the outside of thecase 12 through this through-hole may engage with an engaging portion ofthe drive device and be moved substantially rearward during a loadingoperation of the case 12 into the drive device, such that the door 50 isrotated in the direction of opening the opening 20. That is, obviously,the recording tape cartridge 10 of the present invention is not limitedin any way by structure of the bucket 60 of the drive device.

Furthermore, the structure of the embodiment described above is apreferable structure in which the door 50 is formed in a curved shapecorresponding to a predetermined movement path thereof. However, thepresent invention is not limited thus. For example, a flat plate-formdoor which is resiliently deformable in a plate thickness directionthereof may be provided instead of the door 50, with the upper and lowerguide channels 70 extending as far as the recess portion 30A of thediagonal wall portions 30. By upper and lower end portions of this doorbeing inserted into the guide channels 70, the door can be maintained ina state of being deformed into a curved shape, and the door can be movedalong the guide channels 70 to open and close the opening 20. In such acase, an amount of engagement of the operation projection 52 with theengaging protrusion 68 may be conserved by a restoring force of the flatplate-form door itself, such that the operation projection 52 can belocated at an appropriate position.

Further again, the present invention is not limited to a preferablestructure in which the coil spring 56 is disposed so as to generate theforce component F2. For example, the urging means may be structured by aspiral spring or the like, and may be a structure which does notgenerate the force component F2. For further example, instead of theurging means, locking means which locks the door 50 at the closedposition of the opening 20 when the recording tape cartridge 10 is notin use may be provided.

Still further, a structure in which a magnetic tape T is employed as arecording tape is used in the embodiment described above. However, thepresent invention is not limited thus. It is sufficient that therecording tape is one of long tape-form information recording/replayingmedia which can record information and replay information that has beenrecorded. Of course, the recording tape cartridge relating to thepresent invention can be applied to recording tape of any kind ofrecording/replaying system.

As is explained above, a recording tape cartridge relating to thepresent invention has excellent effects in that a covering member, whichcan reduce size of an accommodation space of the recording tapecartridge in a drive device, can open and close an opening aperture,which has a structure which can minimize length of a drawing-out path ofa recording tape, without interfering with a reel and a leader member,and a drive device side opening means which operates the covering memberto open and close the opening aperture can have a simple structure.

Moreover, a drive device relating to the present invention has anexcellent effect in that an opening aperture of a recording tapecartridge, for drawing out recording tape, can be assuredly opened andclosed.

1. A tape cartridge which is insertable at a tape drive, the tape drivebeing provided with an opening member which is operably engageable withthe tape cartridge at a time of insertion of the tape cartridge andcarrying out at least one of reading and writing of data, the tapecartridge comprising: a case which includes a front wall portion facingin a direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion, and angled relative to the cartridge insertion direction;a tape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; and anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the opening member of the tape drive by anoperation of insertion of the tape cartridge.
 2. The tape cartridge ofclaim 1, wherein the covering member is formed of a resilient membercapable of resiliently deforming during assembly so as to conform to thecircular arc-form movement path.
 3. The tape cartridge of claim 1,wherein the covering member is pre-curved so as to substantially conformto the circular arc-form movement path.
 4. The tape cartridge of claim1, further comprising an urging element which continuously urges thecovering member in a closed position direction.
 5. The tape cartridge ofclaim 4, wherein the urging element urges the covering member in adirection toward the side wall portion of the case and the angled wallportion of the case.
 6. The tape cartridge of claim 1, furthercomprising an elongated slit formed in the side wall portion of the caseand extending along the cartridge insertion direction, the slit enablingrelative engagement of the opening member of the tape drive and theoperation portion at the time of insertion of the tape cartridge.
 7. Thetape cartridge of claim 6, further comprising a wall portion forreinforcement between the slit and the tape access opening, which makesthe slit and the tape access opening non-continuous with one another. 8.The tape cartridge of claim 6, wherein the slit and the tape accessopening are continuous with one another.
 9. The tape cartridge of claim6, wherein the case is structured with an upper case and a lower case,and the slit is formed in either one of the upper case and the lowercase.
 10. The tape cartridge of claim 9, further comprising an urgingelement which continuously urges the covering member in a closedposition direction.
 11. The tape cartridge of claim 10, wherein theurging element urges the covering member in a direction toward the sidewall portion of the case and the angled wall portion of the case. 12.The tape cartridge of claim 11, wherein the case comprises at least oneguide channel provided so as to conform to the circular arc-formmovement path.
 13. The tape cartridge of claim 12, wherein the coveringmember comprises a plurality of guide members which are engageable withthe guide channel.
 14. The tape cartridge of claim 1, wherein the casefurther comprises at least one guide channel provided so as to conformto the circular arc-form movement path.
 15. The tape cartridge of claim14, wherein the covering member comprises a plurality of guide memberswhich are engageable with the guide channel.
 16. The tape cartridge ofclaim 15, wherein the case appears substantially rectangular in planview.
 17. The tape cartridge of claim 16, further comprising a tape anda leader member attached to an end of the tape.
 18. The tape cartridgeof claim 17, wherein the leader member is detachably held at a positionon or at an inner side of a line from one to another of joining portionswhich are located at vicinities of end portions, in plan view, of thetape access opening.
 19. The tape cartridge of claim 18, wherein theleader member comprises a leader pin, and the tape cartridge comprises aholding structure which detachably holds the leader pin at each side ina longitudinal direction of the leader pin.
 20. A tape drive forcarrying out at least one of reading and writing of data at a tapecartridge that includes: a case which includes a front wall portionfacing in a direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion and angled relative to the cartridge insertion direction; atape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; and anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the tape drive by an operation of insertionof the tape cartridge, wherein the tape drive comprises an openingmember which is capable of engaging with the operating portion of thecovering member and moving the covering member in the open positiondirection at a time of insertion of the tape cartridge.
 21. The tapedrive of claim 20, further comprising a bucket which comprises aplurality of guide walls for guiding the tape cartridge.
 22. The tapedrive of claim 21, wherein the opening member is fixedly disposed at thebucket.
 23. The tape drive of claim 21, wherein the bucket furthercomprises a recess provided in a vicinity of the opening member, therecess being capable of non-contactingly receiving the operation portionof the covering member at the time of insertion of the tape cartridge.24. The tape drive of claim 20, wherein the opening member projects in adirection intersecting the direction of insertion of the tape cartridge.